Some in-service deterioration in any mechanical device, such as a military aero-engine, is inevitable. As a result of experiencing any deterioration, an aero-engine will seek a different steady operating point thereby resulting in a variation in the high-pressure spool speeds in order to provide the same thrust to keep aircraft’s performance invariant. Any increase in the high-pressure spool speed results in greater low-cycle fatigue damage for the hot-end components and thereby higher engine’s life-cycle costs. Possessing better knowledge (of the impacts of high-pressure turbine’s erosion upon the low-cycle fatigue life-consumption of aero-engine’s hot-end components) helps the users to take wiser management decisions. For a military aircraft’s mission profile, using bespoke computer simulations, the impacts of turbine erosion for high-pressure turbine-blade’s low-cycle fatigue life-consumption have been predicted.